Roberts was hospitalized after falling ill on a flight to Las Vegas, where he was scheduled to perform, according to the letter by Kyle P. Magee.

During treatment, Magee said Roberts' doctors discovered the brain condition, which is initially thought to be a result of bumps taken over Roberts' long career.

Magee denied initial reports that Roberts lost consciousness on the flight."He was alert and awake while notifying the flight attendants of his pain and shortness of breath. Jake was induced to a 'coma-like' state in order to effectively treat the pneumonia," Magee wrote.

"Drugs or alcohol have no bearing on this event despite the Internet rumors," he added.

Roberts, one of professional wrestling's most iconic stars during the golden era of the late 1980s and early 1990s, was recently inducted into the WWE Hall of Fame prior to Wrestlemania in April.